Our proposed study is a continuation of our investigation of the metabolism of trehalose in the parasitic nematodes, with Ascaris suum as our model system. We need to know how trehalose and glucose, the two major low-molecular weight forms of carbohydrate are interrelated in terms of storage and transport. Accordingly, the enzymes most likely to be regulatory sites will be further examined; these enzymes are: trehalose phosphate synthetase, trehalose phosphate phosphatase and trehalase. The partial purification and characterization already achieved will be expanded. Stabilization of the labile glucosyl transferase activities will be a major focus of attention in this laboratory. Known nematocidal drugs, as well as other compounds, will be examined for their inhibitory activity on the multiple forms of trehalase; we will also study the effects of these compounds on trehalose levels in the worm.